1. Field of the Invention
The present invention relates to a method, apparatus and medium for image communication.
2. Description of the Related Art
With advances in image coding technology, such as JPEG and MPEG, advances, a method for compression coding image data and transmitting it in digital form has been established, and a variety of services including digital TV broadcasting and moving image transmission through the Internet have started. Since a transmission bandwidth is limited in such an image transmission through communication, data, in the form of an image satisfying the needs of a receiver side, is typically transmitted at a minimum definition required. As home computers and high-resolution color printers are widely used, there is a growing need for inputting high-resolution image data into a computer and printing out such an image.
Since moving image transmission such as in TV broadcast service and high-resolution still image transmission are conventionally carried out in separate systems, the image is simply available at a definition designated by the moving image transmission when a desired image frame is picked out from the moving image delivered. Such a definition fails to match the definition of the printout of the high-resolution still image. To this end, a method is contemplated in which the moving image transmission is performed at a standard matching the printout of the high-resolution still image. However, not all services for moving image delivery require the high-resolution standard in the reproducing of a moving image. Since the moving image transmission at the high-resolution standard requires a wider transmission band, there is a difficulty in making the delivery of the moving image, which is typically in need of a multi-channel configuration, compatible with the transmission of the still image at a high definition.
It is an object of the present invention to perform both the transmission of a high-resolution still image and the high-efficiency transmission of a moving image in a compatible fashion.
It is another object of the present invention to transmit easily a high-resolution still image as necessary.
It is yet another object of the present invention to provide an image communication method and an image communication apparatus, having a novel function, in compliance with the IEEE 1394 Standard.
The image communication method of the present invention achieves the above object in the transmission of image data of a plurality of pictures to a receiver side by transmitting the high-resolution information of pictures requested by the receiver side, among the plurality of pictures, through a method of transmission different from that for the image data.
In the method and medium for image communication of the present invention, isochronous transmission is used to transmit moving image data while asynchronous transmission is used to transmit high-resolution information of a predetermined image frame of the moving image data.
In the image communication method of the present invention, image data of a plurality of pictures is received, a signal that identifies a picture, out of a sequence of pictures received, requiring high-resolution information is transmitted and the high-resolution information that is received in response to the identifying signal is combined with the image data to obtain an image.
It is yet another object of the present invention to provide a method and apparatus for image communication featuring a novel function.
These and other objects and features of the present invention will become apparent from the following description of its preferred embodiments in conjunction with the accompanying drawings.